Recently, some on-board systems that respectively work in communication with a mobile device such as a mobile phone have been proposed. Patent literature 1 below describes an on-board electronic system comprising an on-board device mounted on a vehicle and a portable device having a display unit, the portable device being capable of being attached or removed. When the vehicle is running, the on-board device outputs inhibition signal to prohibit display of moving images on the portable device. The portable device prohibits display of moving images upon receipt of the inhibition signal.
Patent literature 2 below describes a technology that connects a mobile phone to an on-board display to enable browsing on a display screen of applications such as a navigation program included the mobile phone.